Gear dependancy and additional training

[Nemrod]

Casey McKinley is one of the WKPP yukity-yuks. He's done more deep cave penetrations than anyone I will ever dive with. His normal trim is about 25* off from the horizontal. His head is slightly up, and his body from his chest to his knees is in a straight line 25* off from his direction of travel. His knees are bent, and his fins are pointed backwards. When he kicks, his fins are directed backwards, so his thrust is directed backwards. He still has perfect buoyancy, so between kicks, there is no change in depth, and he can hover motionless at will.

The point being the force from your fin kick is directed based on the orientation of your kick, not that of your body. The body is just resistance. If you develop a good bent knee frog kick, you can execute it in just about any orientation, even horizontally, like Uncle Pug apparently can!

Tom

Thing is I am not much into guru worship, what somebody is alleged to do or not do via a description over the internet via an observation third hand, sorry, that is not a valid argument, I will stay with what I said, read what I said .

Off axis thrust will impart a rotational moment, scuba divers are not immune to the laws of nature. Maybe it is just that I am trained in engineering and science instead of urban legend-isms. I am also immune to and fully vaccinated against Kool-Aid, flying saucers and little green men.

N <---skeptical and critical analysis always trumps the accepted dogma

 

[Walter]

Walter: Thanks for not responding to the question regarding the danglies I mentioned -- Do you believe it is a skill issue (not being savvy enough to have the right gear) -- or is it a "gear issue" because the gear isn't configured properly (and what this has to do with a BP/W, Long hose, etc. I have no idea).

I did respond to your "dragging Octo" comment. A snorkel keeper solves the problem quite nicely. Sorry I missed responding to the "dragging ... Console." That was so basic, it slipped my mind. I attached a snap bolt to my console about 8 years ago. Prior to that, my console did not drag the ground. The method I used for so many years is quite effective and works even when "LDS has console computers on all its rental regs -- BUT the owner refuses to put anything on the BC's which would allow the renter (of course normally a student) to attach the dangling console." Simply put the console through the left sleeve of the vest (going from outside to inside the vest). When the diver puts on the vest, the console will lie quite neatly on the back of the left leg and will not dangle or drag. The diver always knows where to find the console any time he needs to sneak a peek. Sounds like a skill issue to me.

Walter and Nemrod -- I just wrote a longish reply to your statements that the problem is overweighting -- but then I decided you were probably right and deleted it. Then I decided, maybe we are both right. Here's my issue. You both claim a problem with the 45degree swimmer is that the diver is "overweighted" or else she would ascend when kicking. But then I thought, she may very well be correctly "weighted" but just hasn't balanced herself out with her "Buoyancy Compensator" to make her neutral in the water column -- which is obviously a skills issue. I then decided that what you had meant must be "relatively overweighted" -- that is, overweighted for the amount of lift she is using (not what she could be using).

Very well put.

BUT then I thought -- why doesn't she use her BC to become neutral -- and my answer was, because IF she does use her BC to become neutral (a skills issue) she will then start ascending as Walter described. BECAUSE her gear is so out of balance she has to be "out of trim" when neutral (a gear configuration issue) which means she needs to let air out which means she is "overweighted" (in a relative sense) but now she can control herself in the water column by rototilling.

Excellent point, if she were an inanimate object. She's not. She's a person who can shift her weight and trim herself out regardless of her weight placement (assuming, of course, she isn't wearing all her lead on her ankles). If you are neutrally buoyant in a heads up position, you can get prone by simply leaning forward.

Which comes first -- having gear that won't let you get into "trim" -- not knowing what "good trim" is -- or being "relatively overweighted"? I don't know -- I think knowledge but maybe it is the gear setup.

I've seen some crappy gear, but I've yet to dive any that won't let me get into trim.

 

[Blackwood]

off axis thrust will impart a rotational moment

So in that idealized situation you described in Post 92,

&#8721;M_CG/CB=?

 

[LiteHedded]

Casey McKinley is one of the WKPP yukity-yuks. He's done more deep cave penetrations than anyone I will ever dive with. His normal trim is about 25* off from the horizontal. His head is slightly up, and his body from his chest to his knees is in a straight line 25* off from his direction of travel. His knees are bent, and his fins are pointed backwards. When he kicks, his fins are directed backwards, so his thrust is directed backwards. He still has perfect buoyancy, so between kicks, there is no change in depth, and he can hover motionless at will.

The point being the force from your fin kick is directed based on the orientation of your kick, not that of your body. The body is just resistance. If you develop a good bent knee frog kick, you can execute it in just about any orientation, even horizontally, like Uncle Pug apparently can!

Tom

calling it 25 degrees is being generous

 

[tgsmith]

calling it 25 degrees is being generous

YouTube - WKPP: Turner Sink-Wakulla Springs Connection Dive, 7/28/07

Someone get out their protractor......

 

[FritzCat66]

To my earlier post about not being concerned about whether or not I might be overly gear-dependent or not, I spent the weekend wrestling with a new mask that kind of demonstrates my point, which is that as divers we're already depending on gear simply to breathe, so don't worry about gear dependency, just make sure you know how to use the gear you've got, and know it well.

A mask is one of the simplest pieces of gear we use. Nevertheless it's one of the most critically important ones, if not for pure survival, at least for the purpose of getting underwater to begin with - i.e. to see things. Even cave divers need to see, and even if all your other gear is working perfectly, mask problems can completely ruin a dive for me.

For me, what's most important about selecting a mask is that it fits and doesn't leak. I was lucky enough to be able to purchase my first mask at a scuba discounter in Key Largo who had a big tent sale, with at least three tables of different masks all lined up. Literally dozens of masks from a variety of manufacturers. So I just went down the line and tried every single one, testing for fit. I don't know if I have an unusual face or what, but I could eliminate 70% of the masks immediately because they didn't pass the "suction test".

Anyway, I finally settled on a Cressi mask that fit great, and proceeded to use it for some 70 dives with great results until it suddenly seemed to start leaking randomly. I traced the problem to a broken latch pin on one side that made the strap connection randomly loose.

Otherwise having been happy with the mask, I went shopping for a similar one, and was thrilled to see that Cressi had updated the design of my old one with a newer model that nevertheless maintained the same basic shape and curves, so it still fit my face perfectly.

So, I dove my new mask for the first time this weekend. Oh man, such a simple thing yet so much hassle to get it "broken in"! For me, it's gotta fit perfectly - so I futz with the tension on one side of the strap relative to the tension on the other. And where on the back of my head the strap fits best. I had pre-cleaned the lenses with baking soda, but obviously had not scrubbed the right lens enough so it tended to fog.

Now, as a bearded diver, I am used to a trickle of water coming in from under my nose. I compensate by always exhaling a little air through my nose, which means I have to use really good defog on my lenses to tolerate the constant inrush of humid breath... but even with my usual great defog, the right lens was still frustratingly foggy.

After the first pair of boat dives, I was able to scrub the right lens with toothpaste so I didn't have the fogging problems on my last two dives.

So now I've got this new piece of equipment figured out and well-adapted to me. Does it bother me that I am now "dependent" on this particular mask and can't expect good results with just any rental mask I might grab off the shelf? Heck no! Because now, this is my mask, broken in and working well for me!

And this is just a simple mask! But that's kind of how I feel about all my equipment. I don't see it as a "dependency" so much as a "personalization". But once personalized, it fits me, so I stick with it, and don't worry so much about whether or not I'm dependent on it, or whether it matches somebody else's idea of a "standard configuration" or if I'm "Doing It Right" by their book.

In fact, just the opposite: I like the fact that it's ideosyncratic.

>*< Fritz

 

[Teamcasa]

<snip>
I've seen some crappy gear, but I've yet to dive any that won't let me get into trim.

Exactly my point.

 

[NudeDiver]

All of this talk about gear, dependency, skill and effect on the diver and the ability to dive. It's....interesting.

I wonder if people would have the same bent to their viewpoint if we were talking about gear, dependency, skill and effect on a DRIVER. After all, driving has a strong safety component too. Besides which, a lot more people put themselves in danger and die when driving than they do when diving.

I wonder what a "DIR-compliant" vehicle would look like. Would DIR vehicles have an electric starter, or would DIR divers insist that hand-cranking a vehicle reduces unnecessary complexity? Would something like ABS and airbags be considered safety devices, or unnecessary frills that are non-standard and make your driving too "gear dependent". Would a stereo system be considered a high-tech device that is frowned upon by SERIOUS drivers? Would "electronic stability control" and "automatic transmission" be regarded as something that takes away (or obsoletes) driver skills, and would that be a good thing or a bad thing? What about something like power brakes and steering? Help or hindrance? Would people who went out driving together all be driving the same, standard type of vehicle - a simple, 2-door, subcompact, manual transmission, with no stereo, ABS, airbags or ESC - and completely clean with no trash or candy wrappers on the floor - since - that's the minimum needed to go driving and would allow a driver of one vehicle to seemlessly transmission to driving another vehicle, if needed? Would people seem to have great difficulty when driving a vehicle different from the style they are used to - or are they sufficiently the same that it's really not a big deal. Would people see new vehicle technology as a benefit? Something that, while it may allow drivers to hide bad skills, the fact remains that it enables these drivers to have more fun while being more safe - and makes the task of driving simply easier - and in fact, were it not for the technology that makes driving easier, they wouldn't go driving at all? Or would people insist that the "high skill, manual method" of driving is the best way to be a REAL driver, and if you can't drive that way, then you shouldn't drive at all? Would we go on and on about driver certification agencies, lament the fact that they have low standards, and mourn the days of yonder - when everyone drove manual everything, could change out their own engines, and had a precise understanding of how internal combustion works - down to the molecular level?

Or would people freely accept that what one chooses to drive is simply a matter of choice - neither inherently bad, good, better or lesser - and something that depends on WHY someone is out driving and what they hope to accomplish when they do?

Cheers!
ND

p.s.: good god, could you make that diagram a little smaller?

 

[Walter]

Exactly my point.

I know. I've been agreeing with you throughout this thread.

 

[MXGratefulDiver]

All of this talk about gear, dependency, skill and effect on the diver and the ability to dive. It's....interesting.

I wonder if people would have the same bent to their viewpoint if we were talking about gear, dependency, skill and effect on a DRIVER. After all, driving has a strong safety component too. Besides which, a lot more people put themselves in danger and die when driving than they do when diving.

I wonder what a "DIR-compliant" vehicle would look like. Would DIR vehicles have an electric starter, or would DIR divers insist that hand-cranking a vehicle reduces unnecessary complexity? Would something like ABS and airbags be considered safety devices, or unnecessary frills that are non-standard and make your driving too "gear dependent". Would a stereo system be considered a high-tech device that is frowned upon by SERIOUS drivers? Would "electronic stability control" and "automatic transmission" be regarded as something that takes away (or obsoletes) driver skills, and would that be a good thing or a bad thing? What about something like power brakes and steering? Help or hindrance? Would people who went out driving together all be driving the same, standard type of vehicle - a simple, 2-door, subcompact, manual transmission, with no stereo, ABS, airbags or ESC - and completely clean with no trash or candy wrappers on the floor - since - that's the minimum needed to go driving and would allow a driver of one vehicle to seemlessly transmission to driving another vehicle, if needed? Would people seem to have great difficulty when driving a vehicle different from the style they are used to - or are they sufficiently the same that it's really not a big deal. Would people see new vehicle technology as a benefit? Something that, while it may allow drivers to hide bad skills, the fact remains that it enables these drivers to have more fun while being more safe - and makes the task of driving simply easier - and in fact, were it not for the technology that makes driving easier, they wouldn't go driving at all? Or would people insist that the "high skill, manual method" of driving is the best way to be a REAL driver, and if you can't drive that way, then you shouldn't drive at all? Would we go on and on about driver certification agencies, lament the fact that they have low standards, and mourn the days of yonder - when everyone drove manual everything, could change out their own engines, and had a precise understanding of how internal combustion works - down to the molecular level?

Or would people freely accept that what one chooses to drive is simply a matter of choice - neither inherently bad, good, better or lesser - and something that depends on WHY someone is out driving and what they hope to accomplish when they do?

Cheers!
ND

p.s.: good god, could you make that diagram a little smaller?

FWIW - the term "DIR-compliant" is an internet term, coined to give people who don't understand the first thing about DIR something to talk about.

DIR is less about gear choices than it is about the concept of "predictable behavior". If you want to make comparisons between DIR and driving, you should focus less on the car and more on the rules of the road ...

... Bob (Grateful Diver)